The P-10 optic plate fits perfectly on the Shadow 2.
When I bought my S2, I only had P-10 plates on hand so that's what I used. When I got my S2 optic plate I removed the P-10 plate, bolted on the S2 plate, and they plopped the SRO on it. The SRO fit so loosely on the S2 plate that I immediately unbolted the S2 plate and reinstalled the P-10 plate, which provided a much closer fit to the base of the SRO.
I suspect the recoil bosses on my sample of one (CZUB Shadow 2 plate) were undersized in diameter (out of spec low) because the SRO fit unreasonably loose compared to how close it fit to the recoil bosses on the CZ USA P-10 plate.
YMMV